[webpubsub] Init pr for client protobuf protocol (Azure#24879)

### Packages impacted by this PR
@azure/web-pubsub-client-protobuf

This is the init pr for @azure/web-pubsub-client-protobuf. Please review the package name, dependencies.

### Checklists
- [ ] Added impacted package name to the issue description
- [ ] Does this PR needs any fixes in the SDK Generator?** _(If so, create an Issue in the [Autorest/typescript](https://github.com/Azure/autorest.typescript) repository and link it here)_
- [ ] Added a changelog (if necessary)

Author: zackliu

.vscode/cspell.json

@@ -292,6 +292,10 @@
     {
       "filename": "sdk/web-pubsub/web-pubsub-client/review/web-pubsub-client.api.md",
       "words": ["protobuf"]
+    },
+    {
+      "filename": "sdk/web-pubsub/web-pubsub-client-protobuf/review/web-pubsub-client-protobuf.api.md",
+      "words": ["protobuf"]
     }
   ]
 }